| // Copyright 2020 Joe Drago. All rights reserved. |
| // SPDX-License-Identifier: BSD-2-Clause |
| |
| #include "avifpng.h" |
| #include "avifutil.h" |
| |
| #include "png.h" |
| |
| #include <ctype.h> |
| #include <limits.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| // See libpng-manual.txt, section XI. |
| #if PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5) |
| typedef png_bytep png_iccp_datap; |
| #else |
| typedef png_charp png_iccp_datap; |
| #endif |
| |
| // Converts a hexadecimal string which contains 2-byte character representations of hexadecimal values to raw data (bytes). |
| // hexString may contain values consisting of [A-F][a-f][0-9] in pairs, e.g., 7af2..., separated by any number of newlines. |
| // On success the bytes are filled and AVIF_TRUE is returned. |
| // AVIF_FALSE is returned if fewer than numExpectedBytes hexadecimal pairs are converted. |
| static avifBool avifHexStringToBytes(const char * hexString, size_t hexStringLength, size_t numExpectedBytes, avifRWData * bytes) |
| { |
| avifRWDataRealloc(bytes, numExpectedBytes); |
| size_t numBytes = 0; |
| for (size_t i = 0; (i + 1 < hexStringLength) && (numBytes < numExpectedBytes);) { |
| if (hexString[i] == '\n') { |
| ++i; |
| continue; |
| } |
| if (!isxdigit(hexString[i]) || !isxdigit(hexString[i + 1])) { |
| avifRWDataFree(bytes); |
| fprintf(stderr, "Metadata extraction failed: invalid character at " AVIF_FMT_ZU "\n", i); |
| return AVIF_FALSE; |
| } |
| const char twoHexDigits[] = { hexString[i], hexString[i + 1], '\0' }; |
| bytes->data[numBytes] = (uint8_t)strtol(twoHexDigits, NULL, 16); |
| ++numBytes; |
| i += 2; |
| } |
| |
| if (numBytes != numExpectedBytes) { |
| avifRWDataFree(bytes); |
| fprintf(stderr, "Metadata extraction failed: expected " AVIF_FMT_ZU " tokens but got " AVIF_FMT_ZU "\n", numExpectedBytes, numBytes); |
| return AVIF_FALSE; |
| } |
| return AVIF_TRUE; |
| } |
| |
| // Parses the raw profile string of profileLength characters and extracts the payload. |
| static avifBool avifCopyRawProfile(const char * profile, size_t profileLength, avifRWData * payload) |
| { |
| // ImageMagick formats 'raw profiles' as "\n<name>\n<length>(%8lu)\n<hex payload>\n". |
| if (!profile || (profileLength == 0) || (profile[0] != '\n')) { |
| fprintf(stderr, "Metadata extraction failed: truncated or malformed raw profile\n"); |
| return AVIF_FALSE; |
| } |
| |
| const char * lengthStart = NULL; |
| for (size_t i = 1; i < profileLength; ++i) { // i starts at 1 because the first '\n' was already checked above. |
| if (profile[i] == '\0') { |
| // This should not happen as libpng provides this guarantee but extra safety does not hurt. |
| fprintf(stderr, "Metadata extraction failed: malformed raw profile, unexpected null character at " AVIF_FMT_ZU "\n", i); |
| return AVIF_FALSE; |
| } |
| if (profile[i] == '\n') { |
| if (!lengthStart) { |
| // Skip the name and store the beginning of the string containing the length of the payload. |
| lengthStart = &profile[i + 1]; |
| } else { |
| const char * hexPayloadStart = &profile[i + 1]; |
| const size_t hexPayloadMaxLength = profileLength - (i + 1); |
| // Parse the length, now that we are sure that it is surrounded by '\n' within the profileLength characters. |
| char * lengthEnd; |
| const long expectedLength = strtol(lengthStart, &lengthEnd, 10); |
| if (lengthEnd != &profile[i]) { |
| fprintf(stderr, "Metadata extraction failed: malformed raw profile, expected '\\n' but got '\\x%.2X'\n", *lengthEnd); |
| return AVIF_FALSE; |
| } |
| // No need to check for errno. Just make sure expectedLength is not LONG_MIN and not LONG_MAX. |
| if ((expectedLength <= 0) || (expectedLength == LONG_MAX) || |
| ((unsigned long)expectedLength > (hexPayloadMaxLength / 2))) { |
| fprintf(stderr, "Metadata extraction failed: invalid length %ld\n", expectedLength); |
| return AVIF_FALSE; |
| } |
| // Note: The profile may be malformed by containing more data than the extracted expectedLength bytes. |
| // Be lenient about it and consider it as a valid payload. |
| return avifHexStringToBytes(hexPayloadStart, hexPayloadMaxLength, (size_t)expectedLength, payload); |
| } |
| } |
| } |
| fprintf(stderr, "Metadata extraction failed: malformed or truncated raw profile\n"); |
| return AVIF_FALSE; |
| } |
| |
| static avifBool avifRemoveHeader(const avifROData * header, avifRWData * payload) |
| { |
| if (payload->size > header->size && !memcmp(payload->data, header->data, header->size)) { |
| memmove(payload->data, payload->data + header->size, payload->size - header->size); |
| payload->size -= header->size; |
| return AVIF_TRUE; |
| } |
| return AVIF_FALSE; |
| } |
| |
| // Extracts metadata to avif->exif and avif->xmp unless the corresponding *ignoreExif or *ignoreXMP is set to AVIF_TRUE. |
| // *ignoreExif and *ignoreXMP may be set to AVIF_TRUE if the corresponding Exif or XMP metadata was extracted. |
| // Returns AVIF_FALSE in case of a parsing error. |
| static avifBool avifExtractExifAndXMP(png_structp png, png_infop info, avifBool * ignoreExif, avifBool * ignoreXMP, avifImage * avif) |
| { |
| #ifdef PNG_eXIf_SUPPORTED |
| if (!*ignoreExif) { |
| png_uint_32 exifSize = 0; |
| png_bytep exif = NULL; |
| if (png_get_eXIf_1(png, info, &exifSize, &exif) == PNG_INFO_eXIf) { |
| if ((exifSize == 0) || !exif) { |
| fprintf(stderr, "Exif extraction failed: empty eXIf chunk\n"); |
| return AVIF_FALSE; |
| } |
| avifImageSetMetadataExif(avif, exif, exifSize); |
| // Ignore any Exif parsing failure. |
| (void)avifImageExtractExifOrientationToIrotImir(avif); |
| *ignoreExif = AVIF_TRUE; // Ignore any other Exif chunk. |
| } |
| } |
| #endif // PNG_eXIf_SUPPORTED |
| |
| // HEIF specification ISO-23008 section A.2.1 allows including and excluding the Exif\0\0 header from AVIF files. |
| // The PNG 1.5 extension mentions the omission of this header for the modern standard eXIf chunk. |
| const avifROData exifApp1Header = { (const uint8_t *)"Exif\0\0", 6 }; |
| const avifROData xmpApp1Header = { (const uint8_t *)"http://ns.adobe.com/xap/1.0/\0", 29 }; |
| |
| // tXMP could be retrieved using the png_get_unknown_chunks() API but tXMP is deprecated |
| // and there is no PNG file example with a tXMP chunk lying around, so it is not worth the hassle. |
| |
| png_textp text = NULL; |
| const png_uint_32 numTextChunks = png_get_text(png, info, &text, NULL); |
| for (png_uint_32 i = 0; (!*ignoreExif || !*ignoreXMP) && (i < numTextChunks); ++i, ++text) { |
| png_size_t textLength = text->text_length; |
| #ifdef PNG_iTXt_SUPPORTED |
| if ((text->compression == PNG_ITXT_COMPRESSION_NONE) || (text->compression == PNG_ITXT_COMPRESSION_zTXt)) { |
| textLength = text->itxt_length; |
| } |
| #endif |
| |
| if (!*ignoreExif && !strcmp(text->key, "Raw profile type exif")) { |
| if (!avifCopyRawProfile(text->text, textLength, &avif->exif)) { |
| return AVIF_FALSE; |
| } |
| avifRemoveHeader(&exifApp1Header, &avif->exif); // Ignore the return value because the header is optional. |
| *ignoreExif = AVIF_TRUE; // Ignore any other Exif chunk. |
| } else if (!*ignoreXMP && !strcmp(text->key, "Raw profile type xmp")) { |
| if (!avifCopyRawProfile(text->text, textLength, &avif->xmp)) { |
| return AVIF_FALSE; |
| } |
| avifRemoveHeader(&xmpApp1Header, &avif->xmp); // Ignore the return value because the header is optional. |
| *ignoreXMP = AVIF_TRUE; // Ignore any other XMP chunk. |
| } else if (!strcmp(text->key, "Raw profile type APP1")) { |
| // This can be either Exif, XMP or something else. |
| avifRWData metadata = { NULL, 0 }; |
| if (!avifCopyRawProfile(text->text, textLength, &metadata)) { |
| return AVIF_FALSE; |
| } |
| if (!*ignoreExif && avifRemoveHeader(&exifApp1Header, &metadata)) { |
| avifRWDataFree(&avif->exif); |
| avif->exif = metadata; |
| *ignoreExif = AVIF_TRUE; // Ignore any other Exif chunk. |
| } else if (!*ignoreXMP && avifRemoveHeader(&xmpApp1Header, &metadata)) { |
| avifRWDataFree(&avif->xmp); |
| avif->xmp = metadata; |
| *ignoreXMP = AVIF_TRUE; // Ignore any other XMP chunk. |
| } else { |
| avifRWDataFree(&metadata); // Discard chunk. |
| } |
| } else if (!*ignoreXMP && !strcmp(text->key, "XML:com.adobe.xmp")) { |
| if (textLength == 0) { |
| fprintf(stderr, "XMP extraction failed: empty XML:com.adobe.xmp payload\n"); |
| return AVIF_FALSE; |
| } |
| avifImageSetMetadataXMP(avif, (const uint8_t *)text->text, textLength); |
| *ignoreXMP = AVIF_TRUE; // Ignore any other XMP chunk. |
| } |
| } |
| return AVIF_TRUE; |
| } |
| |
| // Note on setjmp() and volatile variables: |
| // |
| // K & R, The C Programming Language 2nd Ed, p. 254 says: |
| // ... Accessible objects have the values they had when longjmp was called, |
| // except that non-volatile automatic variables in the function calling setjmp |
| // become undefined if they were changed after the setjmp call. |
| // |
| // Therefore, 'rowPointers' is declared as volatile. 'rgb' should be declared as |
| // volatile, but doing so would be inconvenient (try it) and since it is a |
| // struct, the compiler is unlikely to put it in a register. 'readResult' and |
| // 'writeResult' do not need to be declared as volatile because they are not |
| // modified between setjmp and longjmp. But GCC's -Wclobbered warning may have |
| // trouble figuring that out, so we preemptively declare them as volatile. |
| |
| avifBool avifPNGRead(const char * inputFilename, |
| avifImage * avif, |
| avifPixelFormat requestedFormat, |
| uint32_t requestedDepth, |
| avifChromaDownsampling chromaDownsampling, |
| avifBool ignoreICC, |
| avifBool ignoreExif, |
| avifBool ignoreXMP, |
| uint32_t * outPNGDepth) |
| { |
| volatile avifBool readResult = AVIF_FALSE; |
| png_structp png = NULL; |
| png_infop info = NULL; |
| png_bytep * volatile rowPointers = NULL; |
| |
| avifRGBImage rgb; |
| memset(&rgb, 0, sizeof(avifRGBImage)); |
| |
| FILE * f = fopen(inputFilename, "rb"); |
| if (!f) { |
| fprintf(stderr, "Can't open PNG file for read: %s\n", inputFilename); |
| goto cleanup; |
| } |
| |
| uint8_t header[8]; |
| size_t bytesRead = fread(header, 1, 8, f); |
| if (bytesRead != 8) { |
| fprintf(stderr, "Can't read PNG header: %s\n", inputFilename); |
| goto cleanup; |
| } |
| if (png_sig_cmp(header, 0, 8)) { |
| fprintf(stderr, "Not a PNG: %s\n", inputFilename); |
| goto cleanup; |
| } |
| |
| png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); |
| if (!png) { |
| fprintf(stderr, "Cannot init libpng (png): %s\n", inputFilename); |
| goto cleanup; |
| } |
| info = png_create_info_struct(png); |
| if (!info) { |
| fprintf(stderr, "Cannot init libpng (info): %s\n", inputFilename); |
| goto cleanup; |
| } |
| |
| if (setjmp(png_jmpbuf(png))) { |
| fprintf(stderr, "Error reading PNG: %s\n", inputFilename); |
| goto cleanup; |
| } |
| |
| png_init_io(png, f); |
| png_set_sig_bytes(png, 8); |
| png_read_info(png, info); |
| |
| if (!ignoreICC) { |
| char * iccpProfileName = NULL; |
| int iccpCompression = 0; |
| unsigned char * iccpData = NULL; |
| png_uint_32 iccpDataLen = 0; |
| if (png_get_iCCP(png, info, &iccpProfileName, &iccpCompression, (png_iccp_datap *)&iccpData, &iccpDataLen) == PNG_INFO_iCCP) { |
| avifImageSetProfileICC(avif, iccpData, iccpDataLen); |
| } |
| // Note: There is no support for the rare "Raw profile type icc" or "Raw profile type icm" text chunks. |
| // TODO(yguyon): Also check if there is a cICp chunk (https://github.com/AOMediaCodec/libavif/pull/1065#discussion_r958534232) |
| } |
| |
| int rawWidth = png_get_image_width(png, info); |
| int rawHeight = png_get_image_height(png, info); |
| png_byte rawColorType = png_get_color_type(png, info); |
| png_byte rawBitDepth = png_get_bit_depth(png, info); |
| |
| if (rawColorType == PNG_COLOR_TYPE_PALETTE) { |
| png_set_palette_to_rgb(png); |
| } |
| |
| if ((rawColorType == PNG_COLOR_TYPE_GRAY) && (rawBitDepth < 8)) { |
| png_set_expand_gray_1_2_4_to_8(png); |
| } |
| |
| if (png_get_valid(png, info, PNG_INFO_tRNS)) { |
| png_set_tRNS_to_alpha(png); |
| } |
| |
| if ((rawColorType == PNG_COLOR_TYPE_RGB) || (rawColorType == PNG_COLOR_TYPE_GRAY) || (rawColorType == PNG_COLOR_TYPE_PALETTE)) { |
| png_set_filler(png, 0xFFFF, PNG_FILLER_AFTER); |
| } |
| |
| if ((rawColorType == PNG_COLOR_TYPE_GRAY) || (rawColorType == PNG_COLOR_TYPE_GRAY_ALPHA)) { |
| png_set_gray_to_rgb(png); |
| } |
| |
| int imgBitDepth = 8; |
| if (rawBitDepth == 16) { |
| png_set_swap(png); |
| imgBitDepth = 16; |
| } |
| |
| if (outPNGDepth) { |
| *outPNGDepth = imgBitDepth; |
| } |
| |
| png_read_update_info(png, info); |
| |
| avif->width = rawWidth; |
| avif->height = rawHeight; |
| avif->yuvFormat = requestedFormat; |
| if (avif->yuvFormat == AVIF_PIXEL_FORMAT_NONE) { |
| if (avif->matrixCoefficients == AVIF_MATRIX_COEFFICIENTS_IDENTITY) { |
| // Identity is only valid with YUV444. |
| avif->yuvFormat = AVIF_PIXEL_FORMAT_YUV444; |
| } else if ((rawColorType == PNG_COLOR_TYPE_GRAY) || (rawColorType == PNG_COLOR_TYPE_GRAY_ALPHA)) { |
| avif->yuvFormat = AVIF_PIXEL_FORMAT_YUV400; |
| } else { |
| avif->yuvFormat = AVIF_APP_DEFAULT_PIXEL_FORMAT; |
| } |
| } |
| avif->depth = requestedDepth; |
| if (avif->depth == 0) { |
| if (imgBitDepth == 8) { |
| avif->depth = 8; |
| } else { |
| avif->depth = 12; |
| } |
| } |
| |
| avifRGBImageSetDefaults(&rgb, avif); |
| rgb.chromaDownsampling = chromaDownsampling; |
| rgb.depth = imgBitDepth; |
| avifRGBImageAllocatePixels(&rgb); |
| rowPointers = (png_bytep *)malloc(sizeof(png_bytep) * rgb.height); |
| for (uint32_t y = 0; y < rgb.height; ++y) { |
| rowPointers[y] = &rgb.pixels[y * rgb.rowBytes]; |
| } |
| png_read_image(png, rowPointers); |
| if (avifImageRGBToYUV(avif, &rgb) != AVIF_RESULT_OK) { |
| fprintf(stderr, "Conversion to YUV failed: %s\n", inputFilename); |
| goto cleanup; |
| } |
| |
| // Read Exif metadata at the beginning of the file. |
| if (!avifExtractExifAndXMP(png, info, &ignoreExif, &ignoreXMP, avif)) { |
| goto cleanup; |
| } |
| // Read Exif or XMP metadata at the end of the file if there was none at the beginning. |
| if (!ignoreExif || !ignoreXMP) { |
| png_read_end(png, info); |
| if (!avifExtractExifAndXMP(png, info, &ignoreExif, &ignoreXMP, avif)) { |
| goto cleanup; |
| } |
| } |
| readResult = AVIF_TRUE; |
| |
| cleanup: |
| if (f) { |
| fclose(f); |
| } |
| if (png) { |
| png_destroy_read_struct(&png, &info, NULL); |
| } |
| if (rowPointers) { |
| free(rowPointers); |
| } |
| avifRGBImageFreePixels(&rgb); |
| return readResult; |
| } |
| |
| avifBool avifPNGWrite(const char * outputFilename, const avifImage * avif, uint32_t requestedDepth, avifChromaUpsampling chromaUpsampling, int compressionLevel) |
| { |
| volatile avifBool writeResult = AVIF_FALSE; |
| png_structp png = NULL; |
| png_infop info = NULL; |
| png_bytep * volatile rowPointers = NULL; |
| FILE * volatile f = NULL; |
| |
| avifRGBImage rgb; |
| memset(&rgb, 0, sizeof(avifRGBImage)); |
| |
| volatile int rgbDepth = requestedDepth; |
| if (rgbDepth == 0) { |
| if (avif->depth > 8) { |
| rgbDepth = 16; |
| } else { |
| rgbDepth = 8; |
| } |
| } |
| |
| avifBool monochrome8bit = (avif->yuvFormat == AVIF_PIXEL_FORMAT_YUV400) && !avif->alphaPlane && (avif->depth == 8) && |
| (rgbDepth == 8); |
| |
| int colorType; |
| if (monochrome8bit) { |
| colorType = PNG_COLOR_TYPE_GRAY; |
| } else { |
| avifRGBImageSetDefaults(&rgb, avif); |
| rgb.chromaUpsampling = chromaUpsampling; |
| rgb.depth = rgbDepth; |
| colorType = PNG_COLOR_TYPE_RGBA; |
| if (!avif->alphaPlane) { |
| colorType = PNG_COLOR_TYPE_RGB; |
| rgb.format = AVIF_RGB_FORMAT_RGB; |
| } |
| avifRGBImageAllocatePixels(&rgb); |
| if (avifImageYUVToRGB(avif, &rgb) != AVIF_RESULT_OK) { |
| fprintf(stderr, "Conversion to RGB failed: %s\n", outputFilename); |
| goto cleanup; |
| } |
| } |
| |
| f = fopen(outputFilename, "wb"); |
| if (!f) { |
| fprintf(stderr, "Can't open PNG file for write: %s\n", outputFilename); |
| goto cleanup; |
| } |
| |
| png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); |
| if (!png) { |
| fprintf(stderr, "Cannot init libpng (png): %s\n", outputFilename); |
| goto cleanup; |
| } |
| info = png_create_info_struct(png); |
| if (!info) { |
| fprintf(stderr, "Cannot init libpng (info): %s\n", outputFilename); |
| goto cleanup; |
| } |
| |
| if (setjmp(png_jmpbuf(png))) { |
| fprintf(stderr, "Error writing PNG: %s\n", outputFilename); |
| goto cleanup; |
| } |
| |
| png_init_io(png, f); |
| |
| // Don't bother complaining about ICC profile's contents when transferring from AVIF to PNG. |
| // It is up to the enduser to decide if they want to keep their ICC profiles or not. |
| #if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && defined(PNG_SET_OPTION_SUPPORTED) // See libpng-manual.txt, section XII. |
| png_set_option(png, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON); |
| #endif |
| |
| if (compressionLevel >= 0) { |
| png_set_compression_level(png, compressionLevel); |
| } |
| |
| png_set_IHDR(png, info, avif->width, avif->height, rgbDepth, colorType, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); |
| if (avif->icc.data && (avif->icc.size > 0)) { |
| png_set_iCCP(png, info, "libavif", 0, (png_iccp_datap)avif->icc.data, (png_uint_32)avif->icc.size); |
| } |
| png_write_info(png, info); |
| |
| rowPointers = (png_bytep *)malloc(sizeof(png_bytep) * avif->height); |
| if (monochrome8bit) { |
| uint8_t * yPlane = avif->yuvPlanes[AVIF_CHAN_Y]; |
| uint32_t yRowBytes = avif->yuvRowBytes[AVIF_CHAN_Y]; |
| for (uint32_t y = 0; y < avif->height; ++y) { |
| rowPointers[y] = &yPlane[y * yRowBytes]; |
| } |
| } else { |
| for (uint32_t y = 0; y < avif->height; ++y) { |
| rowPointers[y] = &rgb.pixels[y * rgb.rowBytes]; |
| } |
| } |
| |
| if (rgbDepth > 8) { |
| png_set_swap(png); |
| } |
| |
| png_write_image(png, rowPointers); |
| png_write_end(png, NULL); |
| |
| writeResult = AVIF_TRUE; |
| printf("Wrote PNG: %s\n", outputFilename); |
| cleanup: |
| if (f) { |
| fclose(f); |
| } |
| if (png) { |
| png_destroy_write_struct(&png, &info); |
| } |
| if (rowPointers) { |
| free(rowPointers); |
| } |
| avifRGBImageFreePixels(&rgb); |
| return writeResult; |
| } |
